heating_calculator.py

"""
Heating Load Calculator Page

This module implements the heating load calculator interface for the HVAC Load Calculator web application.
It provides a step-by-step form for inputting building information and calculates heating loads
using the ASHRAE method.
"""

import streamlit as st
import pandas as pd
import numpy as np
import plotly.express as px
import plotly.graph_objects as go
import json
import os
import sys
from pathlib import Path
from datetime import datetime

# Add the parent directory to sys.path to import modules
sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))

# Import custom modules
from heating_load import HeatingLoadCalculator
from reference_data import ReferenceData
from utils.validation import validate_input, ValidationWarning
from utils.export import export_data


def load_session_state():
    """Initialize or load session state variables."""
    # Initialize session state for form data
    if 'heating_form_data' not in st.session_state:
        st.session_state.heating_form_data = {
            'building_info': {},
            'building_envelope': {},
            'windows': {},
            'ventilation': {},
            'occupancy': {},
            'results': {}
        }
    
    # Initialize session state for validation warnings
    if 'heating_warnings' not in st.session_state:
        st.session_state.heating_warnings = {
            'building_info': [],
            'building_envelope': [],
            'windows': [],
            'ventilation': [],
            'occupancy': []